I. Field of the Invention
The invention relates to a device for holding down sheet material on a conveyor belt.
II. Description of the Prior Art
Prior known devices of this type are employed, for example, for form feeds in accounting machines, and also in other feed devices and in copying machines. The device serves to hold the sheet material usually paper, on the conveyor belt in such a way that a perfect friction contact is set up between the sheet material and the conveyor belt and mis-feeds cannot occur.
A particular case of application is with the so-called Leporello feeds, which operate using a pin feed as the conveyor belt. In this case, the sheets to be conveyed are provided with a perforation in which pin elements of the conveyor belt engage. A holding-down device is particularly important here in order to achieve trouble-free operation and an accurate mode of action with a low feed noise level when the feed rate is high.
Prior known devices have been somewhat complex and have taken up a relatively large amount of space alongside the conveyor belt. Special lever and adjusting elements have been provided in order to make manual adjustment of the spring-loaded flap possible. In many cases it is required to feed several sheets alongside one another in a machine when, for example, multiple-copy sets are to be processed in accounting machines. It is particularly important in these circumstances that the feed devices should not require too much space.
We have now devised an improved holding down device which is simple in operation and construction and which can be made in relatively compact form.